Device and method for decoding video data

The present disclosure claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 63/451,109, filed on Mar. 9, 2023, entitled “Intra-Template Matching with Fractional Precision,” the content of which is hereby incorporated herein fully by reference in its entirety for all purposes.

The present disclosure generally relates to video coding, and more specifically, to techniques for predicting a block unit based on multiple reference blocks.

Intra template matching is a coding tool for video coding, in which, an encoder and/or a decoder may search a matching block for the current block from the reconstructed area of the current frame.

When the encoder and/or the decoder search the matching block, they merely consider multiple reference blocks, each including multiple previously reconstructed pixels. However, the previously reconstructed pixels may be inadequate to predict all of the block units in the video. In addition, fractional-sample movements are not considered in such a prediction mode.

Thus, different kinds of intra template matching may be required for the encoder and/or the decoder to be able to precisely and efficiently predict and/or reconstruct the block unit.

The present disclosure is directed to a device and method for predicting a block unit based on more than one of integer-sample reference blocks and fractional-sample reference blocks.

In a first aspect of the present disclosure, a method of decoding video data and an electronic device for performing the method are provided. The method includes receiving the video data; determining a block unit from a current frame included in the video data; determining, for the block unit, multiple integer-sample reference blocks and multiple fractional-sample reference blocks from the current frame, wherein: each of the multiple integer-sample reference blocks is located at one of multiple integer-sample positions in the current frame, and each of the multiple fractional-sample reference blocks is located at one of multiple fractional-sample positions in the current frame; determining multiple integer-sample template cost values based on the multiple integer-sample reference blocks; determining multiple fractional-sample template cost values based on the multiple fractional-sample reference blocks; selecting multiple prediction reference blocks from the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values; and reconstructing the block unit based on the multiple prediction reference blocks.

In an implementation of the first aspect of the present disclosure, at least one of the multiple prediction reference blocks is selected from the multiple fractional-sample reference blocks.

An implementation of the first aspect of the present disclosure further includes determining multiple weighting parameters based on the multiple integer-sample template cost values and the fractional-sample template cost values for the multiple prediction reference blocks; weightedly combining the multiple prediction reference blocks based on the multiple weighting parameters to determine a predicted block, wherein reconstructing the block unit is further based on the predicted block.

An implementation of the first aspect of the present disclosure further includes determining an arrangement of the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values, wherein selecting the multiple prediction reference blocks is further based on the arrangement.

An implementation of the first aspect of the present disclosure further includes determining a reference area of the block unit from the current image, wherein: the reference arca is reconstructed prior to reconstructing the block unit, and the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks are determined from the reference area of the block unit.

An implementation of the first aspect of the present disclosure further includes determining, from the reference area, a block template region neighboring the block unit; determining, from the reference area, multiple integer-sample template regions, each neighboring one of the multiple integer-sample reference blocks, wherein each of the multiple integer-sample template cost values is determined by calculating a difference between the block template region and a corresponding one of the multiple integer-sample template regions; and determining, from the reference area, multiple fractional-sample template regions, each neighboring one of the multiple fractional-sample reference blocks, wherein each of the multiple fractional-sample template cost values is determined by calculating a difference between the block template region and a corresponding one of the multiple fractional-sample template regions.

An implementation of the first aspect of the present disclosure further includes sub-sampling the reference area based on the block unit by a sub-sampling factor to determine the multiple integer-sample reference blocks; determining multiple intermediate reference blocks from the multiple integer-sample reference blocks based on the multiple integer-sample template cost values; and determining the multiple fractional-sample reference blocks, each neighboring one of the multiple intermediate reference blocks.

An implementation of the first aspect of the present disclosure further includes determining the sub-sampling factor for the block unit from the video data.

In an implementation of the first aspect of the present disclosure, the reference area includes multiple reconstructed samples reconstructed prior to reconstructing the block unit; and each of the multiple fractional-sample reference blocks is determined by using an interpolation filter to filter, respectively, at least one of the multiple reconstructed samples.

The following disclosure contains specific information pertaining to implementations in the present disclosure. The figures and the corresponding detailed disclosure are directed to example implementations. However, the present disclosure is not limited to these example implementations. Other variations and implementations of the present disclosure will occur to those skilled in the art.

Unless noted otherwise, like or corresponding elements among the figures may be indicated by like or corresponding reference designators. The figures and illustrations in the present disclosure are generally not to scale and are not intended to correspond to actual relative dimensions.

For the purposes of consistency and ease of understanding, features are identified (although, in some examples, not illustrated) by reference designators in the exemplary figures. However, the features in different implementations may differ in other respects and shall not be narrowly confined to what is illustrated in the figures.

The disclosure uses the phrases “in one implementation,” or “in some implementations,” which may refer to one or more of the same or different implementations. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The term “comprising” means “including, but not necessarily limited to” and specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the equivalent.

For purposes of explanation and non-limitation, specific details, such as functional entities, techniques, protocols, and standards, are set forth for providing an understanding of the disclosed technology. Detailed disclosure of well-known methods, technologies, systems, and architectures are omitted so as not to obscure the present disclosure with unnecessary details.

Persons skilled in the art will recognize that any disclosed coding function(s) or algorithm(s) described in the present disclosure may be implemented by hardware, software, or a combination of software and hardware. Disclosed functions may correspond to modules that are software, hardware, firmware, or any combination thereof.

A software implementation may include a program having one or more computer-executable instructions stored on a computer-readable medium, such as memory or other types of storage devices. For example, one or more microprocessors or general-purpose computers with communication processing capability may be programmed with computer-executable instructions and perform the disclosed function(s) or algorithm(s).

The microprocessors or general-purpose computers may be formed of application-specific integrated circuits (ASICs), programmable logic arrays, and/or one or more digital signal processors (DSPs). Although some of the disclosed implementations are oriented to software installed and executing on computer hardware, alternative implementations implemented as firmware, as hardware, or as a combination of hardware and software are well within the scope of the present disclosure. The computer-readable medium includes, but is not limited to, random-access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD ROM), magnetic cassettes, magnetic tape, magnetic disk storage, or any other equivalent medium capable of storing computer-executable instructions. The computer-readable medium may be a non-transitory computer-readable medium.

1 FIG. 100 is a block diagram illustrating a systemhaving a first electronic device and a second electronic device for encoding and decoding video data, in accordance with one or more example implementations of this disclosure.

100 110 120 130 The systemincludes a first electronic device, a second electronic device, and a communication medium.

110 130 120 130 The first electronic devicemay be a source device including any device configured to encode video data and transmit the encoded video data to the communication medium. The second electronic devicemay be a destination device including any device configured to receive encoded video data via the communication mediumand decode the encoded video data.

110 120 130 110 112 114 116 120 122 124 126 110 120 The first electronic devicemay communicate via wire, or wirelessly, with the second electronic devicevia the communication medium. The first electronic devicemay include a source module, an encoder module, and a first interface, among other components. The second electronic devicemay include a display module, a decoder module, and a second interface, among other components. The first electronic devicemay be a video encoder and the second electronic devicemay be a video decoder.

110 120 110 120 110 120 1 FIG. The first electronic deviceand/or the second electronic devicemay be a mobile phone, a tablet, a desktop, a notebook, or other electronic devices.illustrates one example of the first electronic deviceand the second electronic device. The first electronic deviceand second electronic devicemay include greater or fewer components than illustrated or have a different configuration of the various illustrated components.

112 112 The source modulemay include a video capture device to capture new video, a video archive to store previously captured video, and/or a video feed interface to receive the video from a video content provider. The source modulemay generate computer graphics-based data, as the source video, or may generate a combination of live video, archived video, and computer-generated video, as the source video. The video capture device may include a charge-coupled device (CCD) image sensor, a complementary metal-oxide-semiconductor (CMOS) image sensor, or a camera.

114 124 114 124 The encoder moduleand the decoder modulemay each be implemented as any of a variety of suitable encoder/decoder circuitry, such as one or more microprocessors, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SoC), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), discrete logic, software, hardware, firmware, or any combinations thereof. When implemented partially in software, a device may store the program having computer-executable instructions for the software in a suitable, non-transitory computer-readable medium and execute the stored computer-executable instructions using one or more processors to perform the disclosed methods. Each of the encoder moduleand the decoder modulemay be included in one or more encoders or decoders, any of which may be integrated as part of a combined encoder/decoder (CODEC) in a device.

116 126 116 126 130 130 The first interfaceand the second interfacemay utilize customized protocols or follow existing standards or de facto standards including, but not limited to, Ethernet, IEEE 802.11 or IEEE 802.15 series, wireless USB, or telecommunication standards including, but not limited to, Global System for Mobile Communications (GSM), Code-Division Multiple Access 2000 (CDMA2000), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), Worldwide Interoperability for Microwave Access (WiMAX), Third Generation Partnership Project Long-Term Evolution (3GPP-LTE), or Time-Division LTE (TD-LTE). The first interfaceand the second interfacemay each include any device configured to transmit a compliant video bitstream via the communication mediumand to receive the compliant video bitstream via the communication medium.

116 126 116 126 The first interfaceand the second interfacemay include a computer system interface that enables a compliant video bitstream to be stored on a storage device or to be received from the storage device. For example, the first interfaceand the second interfacemay include a chipset supporting Peripheral Component Interconnect (PCI) and Peripheral Component Interconnect Express (PCIe) bus protocols, proprietary bus protocols, Universal Serial Bus (USB) protocols, Inter-Integrated Circuit (I2C) protocols, or any other logical and physical structure(s) that may be used to interconnect peer devices.

122 122 The display modulemay include a display using liquid crystal display (LCD) technology, plasma display technology, organic light-emitting diode (OLED) display technology, or light-emitting polymer display (LPD) technology, with other display technologies used in some other implementations. The display modulemay include a High-Definition display or an Ultra-High-Definition display.

2 FIG. 1 FIG. 124 120 124 2241 2242 2243 2244 2245 2246 2242 22421 22422 124 is a block diagram illustrating a decoder moduleof the second electronic deviceillustrated in, in accordance with one or more example implementations of this disclosure. The decoder modulemay include an entropy decoder (e.g., an entropy decoding unit), a prediction processor (e.g., a prediction processing unit), an inverse quantization/inverse transform processor (e.g., an inverse quantization/inverse transform unit), a summer (e.g., a summer), a filter (e.g., a filtering unit), and a decoded picture buffer (e.g., a decoded picture buffer). The prediction processing unitfurther may include an intra prediction processor (e.g., an intra prediction unit) and an inter prediction processor (e.g., an inter prediction unit). The decoder modulereceives a bitstream, decodes the bitstream, and outputs a decoded video.

2241 126 2241 1 FIG. The entropy decoding unitmay receive the bitstream including multiple syntax elements from the second interface, as shown in, and perform a parsing operation on the bitstream to extract syntax elements from the bitstream. As part of the parsing operation, the entropy decoding unitmay entropy decode the bitstream to generate quantized transform coefficients, quantization parameters, transform data, motion vectors, intra modes, partition information, and/or other syntax information.

2241 2241 2243 2242 The entropy decoding unitmay perform context-adaptive variable length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval partitioning entropy (PIPE) coding, or another entropy coding technique to generate the quantized transform coefficients. The entropy decoding unitmay provide the quantized transform coefficients, the quantization parameters, and the transform data to the inverse quantization/inverse transform unitand provide the motion vectors, the intra modes, the partition information, and other syntax information to the prediction processing unit.

2242 2241 2242 The prediction processing unitmay receive syntax elements, such as motion vectors, intra modes, partition information, and other syntax information, from the entropy decoding unit. The prediction processing unitmay receive the syntax elements including the partition information and divide image frames according to the partition information.

Each of the image frames may be divided into at least one image block according to the partition information. The at least one image block may include a luminance block for reconstructing multiple luminance samples and at least one chrominance block for reconstructing multiple chrominance samples. The luminance block and the at least one chrominance block may be further divided to generate macroblocks, coding tree units (CTUs), coding blocks (CBs), sub-divisions thereof, and/or other equivalent coding units.

2242 During the decoding process, the prediction processing unitmay receive predicted data including the intra mode or the motion vector for a current image block of a specific one of the image frames. The current image block may be the luminance block or one of the chrominance blocks in the specific image frame.

22421 22421 2242 The intra prediction unitmay perform intra-predictive coding of a current block unit relative to one or more neighboring blocks in the same frame as the current block unit based on syntax elements related to the intra mode in order to generate a predicted block. The intra mode may specify the location of reference samples selected from the neighboring blocks within the current frame. The intra prediction unitmay reconstruct multiple chroma components of the current block unit based on multiple luma components of the current block unit when the multiple chroma components is reconstructed by the prediction processing unit.

22421 2242 The intra prediction unitmay reconstruct multiple chroma components of the current block unit based on the multiple luma components of the current block unit when the multiple luma components of the current block unit is reconstructed by the prediction processing unit.

22422 22422 2246 The inter prediction unitmay perform inter-predictive coding of the current block unit relative to one or more blocks in one or more reference image blocks based on syntax elements related to the motion vector in order to generate the predicted block. The motion vector may indicate a displacement of the current block unit within the current image block relative to a reference block unit within the reference image block. The reference block unit may be a block determined to closely match the current block unit. The inter prediction unitmay receive the reference image block stored in the decoded picture bufferand reconstruct the current block unit based on the received reference image blocks.

2243 2243 The inverse quantization/inverse transform unitmay apply inverse quantization and inverse transformation to reconstruct the residual block in the pixel domain. The inverse quantization/inverse transform unitmay apply inverse quantization to the residual quantized transform coefficient to generate a residual transform coefficient and then apply inverse transformation to the residual transform coefficient to generate the residual block in the pixel domain.

The inverse transformation may be inversely applied by the transformation process, such as a discrete cosine transform (DCT), a discrete sine transform (DST), an adaptive multiple transform (AMT), a mode-dependent non-separable secondary transform (MDNSST), a Hypercube-Givens transform (HyGT), a signal-dependent transform, a Karhunen-Loéve transform (KLT), a wavelet transform, an integer transform, a sub-band transform, or a conceptually similar transform. The inverse transformation may convert the residual information from a transform domain, such as a frequency domain, back to the pixel domain, etc. The degree of inverse quantization may be modified by adjusting a quantization parameter.

2244 2242 The summermay add the reconstructed residual block to the predicted block provided by the prediction processing unitto produce a reconstructed block.

2245 2244 2245 122 2245 The filtering unitmay include a deblocking filter, a sample adaptive offset (SAO) filter, a bilateral filter, and/or an adaptive loop filter (ALF) to remove blocking artifacts from the reconstructed block. Additional filters (in loop or post loop) may also be used in addition to the deblocking filter, the SAO filter, the bilateral filter, and the ALF. Such filters are not explicitly illustrated for brevity but may filter the output of the summer. The filtering unitmay output the decoded video to the display moduleor other video receiving units after the filtering unitperforms the filtering process for the reconstructed blocks of the specific image frame.

2246 2242 2246 2246 124 The decoded picture buffermay be a reference picture memory that stores the reference block to be used by the prediction processing unitin decoding the bitstream (e.g., in inter-coding modes). The decoded picture buffermay be formed by any of a variety of memory devices, such as dynamic random-access memory (DRAM), including synchronous DRAM (SDRAM), magneto-resistive RAM (MRAM), resistive RAM (RRAM), or other types of memory devices. The decoded picture buffermay be on-chip with other components of the decoder moduleor off-chip relative to those components.

3 FIG. 300 300 is a flowchart illustrating a method/processfor decoding and/or encoding video data by an electronic device, in accordance with one or more example implementations of this disclosure. The method/processis an example implementation, as there are a variety of ways of decoding the video data.

300 300 1 2 FIGS.and 3 FIG. The method/processmay be performed by an electronic device using the configurations illustrated in, where various elements of these figures may be referenced to describe the method/process. Each block illustrated inmay represent one or more processes, methods, or subroutines performed by an electronic device.

3 FIG. The order in which the blocks appear inis for illustration only, and may not be construed to limit the scope of the present disclosure, thus may be different from what is illustrated. Additional blocks may be added or fewer blocks may be utilized without departing from the scope of the present disclosure.

310 300 124 124 At block, the method/processmay start by the decoder modulereceiving the video data. The video data received by the decoder modulemay include a bitstream.

1 2 FIGS.and 120 110 126 126 124 With reference to, the second electronic devicemay receive the bitstream from an encoder, such as the first electronic device(or other video providers) via the second interface. The second interfacemay provide the bitstream to the decoder module.

320 124 At block, the decoder moduledetermines a block unit from a current frame included in the video data.

1 2 FIGS.and 124 124 124 124 With reference to, the decoder modulemay determine the image frames included in the bitstream when the video data received by the decoder moduleis the bitstream. The current frame may be one of the image frames determined according to the bitstream. The decoder modulemay further divide the current frame to determine the block unit according to partition indications in the bitstream. For example, the decoder modulemay divide the current frame to generate multiple CTUs, and further divide a current CTU included in the CTUs to generate multiple divided blocks and to determine the block unit from the divided blocks according to the partition indications based on any video coding standard. The size of the block unit may be Wb×Hb. In some implementations, the values Wb and Hb may be positive integers (e.g., 4, 8, etc.) that may be equal to, or different from, each other.

330 124 At block, the decoder moduledetermines, for the block unit, multiple integer-sample reference blocks and multiple fractional-sample reference blocks from the current frame.

124 The decoder modulemay determine, from the current frame, a reference area of the block unit. The reference area may be reconstructed prior to reconstructing the block unit. The reference area may include multiple reconstructed samples reconstructed prior to reconstructing the block unit.

124 The decoder modulemay determine, from the current frame, multiple search regions based on a location and the size of the block unit. The search regions of the block unit may be determined from the reference area of the current frame. The search regions of the block unit may be included in the current CTU that includes the block unit and multiple neighboring CTUs neighboring the current CTU. The current CTU and the neighboring CTUs may be included in the reference area of the current frame. The neighboring CTUs may include one or more of a first neighboring CTU located at a top-left side of the current CTU, a second neighboring CTU located above the current CTU, a third neighboring CTU located at an above-right side of the current CTU, and a fourth neighboring CTU located at a left side of the current CTU.

4 4 FIGS.A-B 4 FIG.A 400 411 414 411 400 412 411 413 411 414 411 are schematic illustrations of a block unit and multiple search regions, in accordance with one or more example implementations of this disclosure. In, the block unitmay have multiple search regions-. The search regionmay be a first search region located at a top-left side of the block unitand included in the current CTU. The search regionmay be a second search region located at a top-left side of the first search regionand included in the first neighboring CTU located at the top-left side of the current CTU. The search regionmay be a third search region located above the first search regionand included in the second neighboring CTU located above the current CTU. The search regionmay be a fourth search region located at a left side of the first search regionand included in the fourth neighboring CTU located at the left side of the current CTU.

4 FIG.B 400 431 436 431 400 441 442 443 432 400 444 433 400 432 440 441 442 444 434 400 433 440 442 435 400 434 440 442 436 400 432 440 444 In, the block unitmay have multiple search regions-. The search regionmay be a first search region located over the block unitand included in the first neighboring CTU, the second neighboring CTU, and the third neighboring CTU. The search regionmay be a second search region located neighboring a left side of the block unitand included in the fourth neighboring CTU. The search regionmay be a third search region located neighboring the top-left side of the block unit, located above the search region, and included in the current CTU, the first neighboring CTU, the second neighboring CTU, and the fourth neighboring CTU. The search regionmay be a fourth search region located over the top-left side of the block unit, located at a right side of the search region, and included in the current CTUand the second neighboring CTU. The search regionmay be a fifth search region located over the block unit, located at a right side of the search region, and included in the current CTUand the second neighboring CTU. The search regionmay be a sixth search region located neighboring the left side of the block unit, located at a right side of the search region, and included in the current CTUand the fourth neighboring CTU.

400 400 400 400 400 The size of the search regions may be Ws×Hs and be set based on the size Wb×Hb of the block unit. In some implementations, the width Ws of the search regions may be proportional to the width Wb of the block unit, and the height Hs of the search regions ma be proportional to the width Hb of the block unit. In some implementations, the width Ws of the search regions may be equal to a minimum width value between a first constant value and a first variable value generated by multiplying the width Wb of the block unitby a second constant value. In addition, the height Hs of the search regions may be equal to a minimum height value between the first constant value and a second variable value generated by multiplying the height Hb of the block unitby the second constant value. In some implementations, the first constant value may be equal to a first integer, and the second constant value may be equal to a second integer. In some implementations, the first constant value may be equal to 64, and the second constant value may be equal to 5. It should be noted that the number of search regions and the size of search regions may be changed without departing from the scope of the present disclosure.

124 400 411 412 431 436 400 The decoder modulemay determine, for the block unit, multiple reference blocks including the integer-sample reference blocks and the fractional-sample reference blocks from the search regions (e.g., the search regions-or the search regions-) in the current frame. Thus, the integer-sample reference blocks and the fractional-sample reference blocks may be determined from the reference area of the block unit. The size of the block unitmay be identical to the sizes of the integer-sample reference blocks and the fractional-sample reference blocks.

400 421 413 422 414 4211 400 421 4221 400 422 4 FIG.A 4 FIG.A In some implementations, each of the integer-sample reference blocks may include some of the reconstructed samples reconstructed prior to reconstructing the block unit. For example, a reference block, as shown in, may be one of the integer-sample reference blocks and have some of the reconstructed samples included in the search region. In addition, a reference block, as shown in, may be another one of the integer-sample reference blocks and have some of the reconstructed samples included in the search region. In some implementations, a block vectormay be used to direct from the block unittowards the reference block, and a block vectormay be used to direct from the block unittowards the reference block.

In some implementations, each of the fractional-sample reference blocks may include multiple fractional-samples determined based on the reconstructed samples. Each of the fractional-samples may be determined based on the reconstructed samples in the reference area by using an interpolation filter. Thus, each of the fractional-sample reference blocks may be determined by using the interpolation filter to filter, respectively, at least one of the reconstructed samples.

In some implementations, the fractional-sample reference blocks may be determined based on a fractional precision. The fractional precision may include a half-pel precision, a quarter-pel precision, a 1/16-pel precision, 1/32-pel precision, and/or other fractional precisions. The fractional precision may be determined based on a precision value used in an intra template matching prediction (IntraTMP). In some implementations, a precision flag may be used to determine whether to enable the fractional precision. In some implementations, the precision flag may be included in a syntax header. A syntax level of the syntax header may be higher than, or identical to, a syntax level of a slice header. Thus, the syntax header may be one of the slice header, a tile header, a picture header, a picture parameter set (PPS), a sequence parameter set (SPS), a video parameter set (VPS), etc.

The precision flag may be included in the SPS to indicate whether the fractional precision is enabled for the IntraTMP in a sequence of the video data. For example, the fractional precision may be disabled when the precision flag is equal to 0 and the fractional precision may be enabled when the precision flag is equal to 1. In addition, the precision flag may be included in the slice header to indicate an IntraTMP precision of a current slice including the block unit. In some other implementations, values of the precision flag may further indicate different fractional precisions. For example, the integer precision and a half-pel precision may be enabled when the precision flag is equal to 1 and the integer precision, the half-pel precision, and a quarter-pel precision may be enabled when the precision flag is equal to 2. In some other implementations, the precision flag may be further used as an IntraTMP flag to indicate whether the IntraTMP is enabled. Thus, the IntraTMP may be disabled when the precision flag is equal to zero. In addition, the IntraTMP and the integer precision may be enabled and the fractional precision may be disabled when the precision flag is equal to 1. The IntraTMP, the integer precision, and the half-pel precision may be enabled when the precision flag is equal to 2. The IntraTMP, the integer precision, the half-pel precision, and the quarter-pel precision may be enabled when the precision flag is equal to 3.

5 FIG. 500 523 524 5231 500 523 5241 500 524 Each of the integer-sample reference blocks may be located at one of multiple integer-sample positions in the current frame, and each of the fractional-sample reference blocks may be located at one of multiple fractional-sample positions in the current frame.is a schematic illustration of a block unit, an integer-sample reference block, and a fractional-sample reference block, in accordance with one or more example implementations of this disclosure. In some implementations, a block vectormay be used to have a direction from the block unittowards the reference block, and a block vectormay be used to have a direction from the block unittowards the reference block.

523 5232 523 524 5242 524 524 524 5242 524 523 The location of the integer-sample reference blockmay be represented by an integer-sample positionof a top-left sample of the integer-sample reference block. The location of the fractional-sample reference blockmay be represented by a fractional-sample positionof a top-left sample of the fractional-sample reference block. Each of the fractional-samples in the fractional-sample reference blockmay be determined by using the interpolation filter to filter, respectively, the neighbors of the reconstructed samples. In some implementations, the top-left sample of the fractional-sample reference blockmay be located at the fractional-sample positionand determined by filtering N neighbors of the reconstructed samples in the reference area. In some implementation, the number N may be an integer, such as 2 or 4. For example, the top-left sample of the fractional-sample reference blockmay be determined by filtering four top-left samples of the integer-sample reference block.

124 124 In some implementations, the decoder modulemay perform a full search on the reference area to determine multiple initial reference blocks. In some such implementations, all of the integer-sample reference blocks may be included in the initial reference blocks during the full search. In some other implementations, all of the integer-sample reference blocks and the fractional-sample reference blocks may be included in the initial reference blocks during the full search. In yet, some other implementations, the decoder modulemay perform a quick search (e.g., a diamond search) on the reference area to determine the initial reference blocks.

124 124 In some implementations, the decoder modulemay sub-sample the reference area based on the block unit by a sub-sampling factor to determine the initial reference blocks. The sub-sampling factor F may be a positive integer greater than one. The sub-sampling factor F may be determined based on at least one of a predefined factor, a syntax element determined from the video data, the size of the block unit Wb×Hb, a size of the current slice, a size of the reference area, or a size of the current frame. For example, the sub-sampling factor may be equal to 2, 3, 5, or any other integer. The decoder modulemay perform a sparse search by using a sparse grid, determined from the sub-sampling factor F, to search the initial reference blocks. Since the sub-sampling factor F may be changed based on the size of the block unit, the size of the current slice, the slice of the reference area, or the size of the current frame, each divided block in the current frame may have a different sub-sampling factor F. Furthermore, the divided blocks in the different frames may also have different sub-sampling factors F. The sub-sampling factor F may be determined for the block unit from the video data.

124 124 The decoder modulemay determine multiple intermediate reference blocks from the initial reference blocks to further perform a refinement search to determine multiple refinement reference blocks. For example, the decoder modulemay sub-sample the reference area based on the block unit by the sub-sampling factor to determine the integer-sample reference blocks, select the intermediate reference blocks from the integer-sample reference blocks, and determine the fractional-sample reference blocks based on the intermediate reference blocks.

3 FIG. 340 124 Referring back to, at block, the decoder moduledetermines multiple integer-sample template cost values based on the multiple integer-sample reference blocks.

1 2 FIGS.and 6 FIG.A 124 600 6001 6005 6001 600 6002 600 6003 600 6004 600 6005 600 6001 6005 600 600 With reference to, the decoder modulemay determine a block template region neighboring the block unit from the reference area of the current frame.is a schematic illustration of a block unitand multiple block adjacent regions-, in accordance with one or more implementations of this disclosure. A first block adjacent regionmay be a left block adjacent region located at a left side of the block unit, a second block adjacent regionmay be an above block adjacent region located above the block unit, a third block adjacent regionmay be an above-left block adjacent region located at a top-left side of the block unit, a fourth block adjacent regionmay be a bottom-left block adjacent region located at a bottom-left side of the block unit, and a fifth block adjacent regionmay be an above-right block adjacent region located at an above-right side of the block unit. The block adjacent regions-may be reconstructed prior to reconstructing the block unit. In some implementations, the size of the block template region may be determined based on the size of the block unit.

124 6001 6005 600 124 6001 6005 600 The decoder modulemay use at least one of the block adjacent regions-as a block template region for predicting the block unit. In some implementations, the decoder modulemay use all of the block adjacent regions-as the block template region for predicting the block unit.

124 625 6251 6255 6251 6255 625 6251 6255 6001 6005 6251 6255 625 6001 6005 600 6 FIG.B The decoder modulemay determine multiple integer-sample template regions from the reference area of the block unit. Each of the integer-sample template regions may neighbor one of the integer-sample reference blocks.is a schematic illustration of a reference blockand multiple reference adjacent regions-, in accordance with one or more implementations of this disclosure. Each of the reference adjacent regions-may neighbor the reference block. The shape and the size of the reference adjacent regions-may be identical to the shape and the size of the block adjacent regions-. The relative locations between the reference adjacent regions-and the reference blockmay be identical to the relative locations between the block adjacent regions-and the block unit.

625 600 6251 6255 600 When the reference blockof the block unitis one of the integer-sample reference blocks, at least one of the reference adjacent regions-may be determined as a corresponding one of the integer-sample template regions. The relative locations between the one of the integer-sample reference blocks and the corresponding one of the integer-sample template regions may be identical to the location between the block unitand the block template region. The shape and the size of the integer-sample template regions may be identical to the shape and the size of the block template region.

124 124 The decoder modulemay determine the integer-sample template cost values based on the integer-sample reference blocks. Each of the integer-sample template cost values may be determined by calculating a difference between the block template region and a corresponding one of the integer-sample template regions. Since the block template region and the integer-sample template regions are reconstructed prior to reconstructing the block unit, the decoder modulemay directly receive multiple reconstructed results of the block template region and the integer-sample template regions.

124 The decoder modulemay derive the integer-sample template cost values between the block template region and the integer-sample template regions using an intra template matching. The intra template matching (TM) may be used for calculating the difference between the block template region and each of the integer-sample template regions. The reconstructed result may include the reconstructed samples having multiple reconstructed block samples of the block template region and multiple reconstructed reference samples for each of the integer-sample template regions. Thus, the integer-sample template cost value for each of the integer-sample template regions may be an integer-sample TM cost value determined by comparing the reconstructed block samples of the block template region with the reconstructed reference samples for a corresponding one of the integer-sample template regions.

The difference between the reconstructed block samples of the block template region and the reconstructed reference samples of the corresponding one of the integer-sample template regions may be calculated based on a Mean Squared Error (MSE) calculation. In addition, the difference between the block template region and each of the integer-sample template regions may be calculated based on a Sum of Absolute Difference (SAD) calculation. In some implementations, the difference between the block template region and each of the integer-sample template regions may be calculated based on a Sum of Absolute Transformed Difference (SATD) calculation. In some implementations, the difference between the block template region and each of the integer-sample template regions may be calculated based on a mean-removed sum of absolute difference (MR-SAD) calculation.

124 124 124 124 124 In some implementations, when the initial reference blocks are determined from the sparce search, the decoder modulemay use the integer-sample template cost values of the initial reference blocks to determine the intermediate reference blocks. The decoder modulemay determine M intermediate reference blocks from the initial reference blocks based on the cost values. When the initial reference blocks are the integer-sample reference blocks, the decoder modulemay determine M intermediate reference blocks from the integer-sample reference blocks based on the integer-sample template cost values. The decoder modulemay select M integer-sample reference blocks having M minimum values of the integer-sample template cost values. When the intermediate reference blocks are determined, the decoder modulemay further determine the refinement reference blocks based on the intermediate reference blocks.

In some other implementations, since the initial reference blocks may be determined based on the sub-sampling factors, the refinement reference blocks may further include some integer-sample reference blocks each neighboring one of the intermediate reference blocks and different from the initial reference blocks. For example, when the sub-sampling factor F is equal to 3 and the fractional precision is the half-pel precision, the number of the refinement reference blocks for each of the intermediate reference blocks may be equal to 5×5.

3 FIG. 350 124 Referring back to, at block, the decoder moduledetermines multiple fractional-sample template cost values based on the multiple fractional-sample reference blocks.

1 2 FIGS.and 124 With reference to, the decoder modulemay determine multiple fractional-sample template regions from the reference area of the block unit. Each of the fractional-sample template regions may neighbor one of the fractional-sample reference blocks.

6 FIG.B 625 600 6251 6255 600 With reference to, when the reference blockof the block unitis one of the fractional-sample reference blocks, at least one of the reference adjacent regions-may be determined as a corresponding one of the fractional-sample template regions. The relative locations between the one of the fractional-sample reference blocks and the corresponding one of the fractional-sample template regions may be identical to the relative locations between the block unitand the block template region. The shape and the size of the fractional-sample template regions may be identical to the shape and the size of the block template region.

124 The decoder modulemay determine the fractional-sample template cost values based on the fractional-sample reference blocks. Each of the fractional-sample template cost values may be determined by calculating a difference between the block template region and a corresponding one of the fractional-sample template regions.

124 The decoder modulemay derive the fractional-sample template cost values between the block template region and the fractional-sample template regions by the intra template matching. The intra TM may be used for calculating the difference between the block template region and each of the fractional-sample template regions. Since the reconstructed result may include the reconstructed samples having the reconstructed reference samples for the integer-sample template regions, each of the fractional-sample reference blocks may be determined by using an interpolation filter to filter, respectively, at least one of the reconstructed reference samples to generate multiple interpolated samples. Thus, the fractional-sample template cost value for each of the fractional-sample template regions may be a fractional-sample TM cost value determined by comparing the reconstructed block samples of the block template region with the interpolated samples for a corresponding one of the fractional-sample template regions. The interpolation filter may include multiple interpolation filter coefficients fC and fG.

The difference between the reconstructed block samples of the block template region and the interpolated samples of a corresponding one of the fractional-sample template regions may be calculated based on the MSE calculation. In addition, the difference between the block template region and each of the fractional-sample template regions may be calculated based on the SAD calculation. In some implementations, the difference between the block template region and each of the fractional-sample template regions may be calculated based on the SATD calculation. In some implementations, the difference between the block template region and each of the fractional-sample template regions may be calculated based on the MR-SAD calculation.

3 FIG. 360 124 Referring back to, at block, the decoder moduleselects multiple prediction reference blocks from the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values.

1 2 FIGS.and 124 With reference to, the decoder modulemay determine an arrangement of the integer-sample reference blocks and the fractional-sample reference blocks based on the integer-sample template cost values and the fractional-sample template cost values, and select the prediction reference blocks based on the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks. In some implementations, at least one of the prediction reference blocks may be selected from the fractional-sample reference blocks.

124 The decoder modulemay reorder the integer-sample reference blocks and the fractional-sample reference blocks based on the determined arrangement. In some implementations, the integer-sample reference blocks and the fractional-sample reference blocks may be reordered in an ascending order or a descending order of the integer-sample template cost values and the fractional-sample template cost values.

Before the arrangement is determined based on the integer-sample template cost values and the fractional-sample template cost values, the integer-sample reference blocks and the fractional-sample reference blocks may be ordered based on one or more arbitrary rules. The integer-sample reference blocks and the fractional-sample reference blocks may be reordered in the ascending order of the integer-sample template cost values and the fractional-sample template cost values. Thus, when the integer-sample template cost value of a specific one of the integer-sample reference blocks is less than the integer-sample template cost values of the other integer-sample reference blocks and all of the fractional-sample template cost values, the specific integer-sample reference block may be moved forward to be a first reference block based on the determined arrangement. In other words, the specific integer-sample reference block may be moved to be the first reference block when the integer-sample template cost value of the specific integer-sample reference block is the minimum value of the integer-sample template cost values and the fractional-sample template cost values.

1 2 3 1 2 3 1 2 3 1 2 3 3 2 1 3 2 1 1 2 3 1 2 3 1 2 3 1 2 3 In addition, the specific integer-sample reference block may be moved to be the last one of the reference blocks when the integer-sample template cost value of the specific integer-sample reference block is the maximum value of the integer-sample template cost values and the fractional-sample template cost values. When the fractional-sample template cost value of a specific one of the fractional-sample reference blocks is less than the fractional-sample template cost values of the other fractional-sample reference blocks and all of the integer-sample template cost values, the specific fractional-sample reference block may be moved forward to be a first reference block based on the determined arrangement. For example, the integer-sample reference blocks may include three integer-sample reference blocks IB, IB, and IBhaving, respectively, three integer-sample template cost values IC, IC, and IC. In addition, the fractional-sample reference blocks may include three fractional-sample reference blocks FB, FB, and FBhaving, respectively, three fractional-sample template cost values FC, FC, and FC. When a value order of the three integer-sample template cost values and the three fractional-sample template cost values is IC>FC>IC>FC>IC>FC, the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks may be changed from an original order of the integer-sample reference blocks IB, IB, and IBand the fractional-sample reference blocks FB, FB, and FBto a new order of the six reference blocks FB, IB, FB, IB, FB, and IB.

124 The arrangement may be further determined by adjusting the new order of the integer-sample reference blocks and the fractional-sample reference blocks based on a diversity criterion. The decoder modulemay determine a difference value between two of the integer-sample template cost values and the fractional-sample template cost values selected from two neighbors of the integer-sample reference blocks and the fractional-sample reference blocks ordered in the new order. When the difference value is less than or equal to a diversity threshold, the last one of the two neighbors of the integer-sample reference blocks and the fractional-sample reference blocks may be moved backward.

124 124 The decoder modulemay select K reference blocks having the least cost values from the integer-sample reference blocks and the fractional-sample reference blocks and add the selected reference blocks to a reference list. The number K, being a positive integer, may be equal to the number of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list, and less than the total number of the integer-sample reference blocks and the fractional-sample reference blocks. In other words, the decoder modulemay select the first to the K-th reference blocks ordered based on the determined arrangement when the integer-sample reference blocks and the fractional-sample reference blocks are reordered in the ascending order of the integer-sample template cost values and the fractional-sample template cost values to generate the determined arrangement. Each of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list may have a reference index value. Thus, the reference index values for the reference list may be within an index range of 0 to K−1 since the number of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list is equal to K.

124 0 1 The decoder modulemay determine the prediction reference blocks from the integer-sample reference blocks and the fractional-sample reference blocks based on at least one of the determined arrangement or multiple reference block indices of the block unit determined based on the bitstream. The reference block indices may include multiple indications (e.g., intra TMP_idxand intra TMP_idx). In some implementations, the multiple minimum values of the integer-sample template cost values and the fractional-sample template cost values may be determined, and then the integer-sample reference blocks and the fractional-sample reference blocks corresponding to the multiple minimum values of the integer-sample template cost values and the fractional-sample template cost values may be directly determined as the prediction reference blocks without parsing the reference block indices. Thus, the number of bits in the bitstream may be reduced.

In some implementations, at least one of the prediction reference blocks may be selected from the fractional-sample reference blocks. Thus, at least one minimum value of the fractional-sample template cost values may be determined, and then at least one of the fractional-sample reference blocks corresponding to the at least one minimum value of the fractional-sample template cost values may be directly determined as the at least one of the prediction reference blocks without parsing the reference block indices. In addition, zero or more minimum values of the integer-sample template cost values may be determined, and then zero or more of the integer-sample reference blocks corresponding to the zero or more minimum values of the integer-sample template cost values may be directly determined as the other prediction reference blocks without parsing the reference block indices. In some implementations, the number of the zero or more of the integer-sample reference blocks may be determined based on the number of the prediction reference blocks and the number of the at least one of the fractional-sample reference blocks. For example, when all of the prediction reference blocks are selected from the fractional-sample reference blocks, the number of the integer-sample reference blocks included in the prediction reference blocks may be equal to zero.

In some implementations, the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement may be divided into multiple reference block groups. In some implementations, the reference block index may be parsed for the block unit for selecting one of the reference block groups. Thus, all of the prediction reference blocks may be included in the selected one of the reference block groups. In some other implementations, the reference list including the selected reference blocks may be divided into multiple listed block groups. The reference block index may be parsed for the block unit for selecting one of the listed block groups. Thus, all of the prediction reference blocks may be included in the one of the listed block groups.

In some implementations, the reference block indices may be parsed for the block unit for selecting the prediction reference blocks from the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement. In some implementations, the reference block indices may be parsed for the block unit for selecting the prediction reference blocks from the reference list. In some implementations, the reference block having a lower cost value may have a lower reference index value. Thus, since the reference block having a lower cost value may be more easily selected than the reference block having a higher cost value, the number of bits in the bitstream may also be reduced.

In some implementations, at least one of the prediction reference blocks may be selected from the fractional-sample reference blocks. Thus, at least one of the reference block indices may be parsed for the block unit for selecting the at least one of the prediction reference blocks only from the fractional-sample reference blocks arranged based on the determined arrangement. In addition, the other reference block indices may be parsed for the block unit for selecting the other prediction reference blocks only from the integer-sample reference blocks arranged based on the determined arrangement. In some implementations, one of the reference block indices may be parsed for the block unit for selecting one of the prediction reference blocks only from the fractional-sample reference blocks arranged based on the determined arrangement. In addition, the other reference block indices may be parsed for the block unit for selecting the other prediction reference blocks from the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement.

3 FIG. 370 124 Referring back to, at block, the decoder modulereconstructs the block unit based on the multiple prediction reference blocks.

1 2 FIGS.and 124 124 With reference to, the decoder modulemay determine multiple weighting parameters based on the integer-sample template cost values and the fractional-sample template cost values for the prediction reference blocks. The decoder modulemay compare the integer-sample template cost values and the fractional-sample template cost values of the prediction reference blocks to determine the weighting parameters. For example, the number of the prediction reference blocks may be equal to Nb, where the number Nb may be a positive integer greater than 1. Thus, the weighting parameters of the Nb prediction reference blocks may be determined based on the following functions:

RBi 1 2 N where the numbers wis a weighting parameter of i-th prediction reference block, RC, RC, . . . , and RCare the cost values of the prediction reference blocks, and the number i are less than or equal to the number Nb. When the i-th prediction reference block is one of the integer-sample reference blocks, the cost value of the i-th prediction reference block is one of the integer-sample template cost values corresponding to the one of the integer-sample reference blocks. When the i-th prediction reference block is one of the fractional-sample reference blocks, the cost value of the i-th prediction reference block is one of the fractional-sample template cost values corresponding to the one of the fractional-sample reference blocks.

124 124 The decoder modulemay predict the block unit based on the prediction reference blocks and the weighting parameters. The decoder modulemay weightedly combine the prediction reference blocks to determine a predicted block of the block unit based on the prediction reference blocks and the weighting parameters.

124 124 124 300 The decoder modulemay reconstruct the block unit based on the predicted block. The decoder modulemay determine multiple residual components from the bitstream for the block unit and add the residual components into the predicted block to reconstruct the block unit. The decoder modulemay reconstruct all of the other block units in the image frame for reconstructing the image frame and the video. The method/processmay then end.

7 FIG. 700 700 is a flowchart illustrating a method/processfor decoding and/or encoding video data by an electronic device, in accordance with one or more example implementations of this disclosure. The method/processis an example implementation, as there are a variety of ways of decoding the video data.

700 700 1 2 FIGS.and 7 FIG. The method/processmay be performed by an electronic device using the configurations illustrated in, where various elements of these figures may be referenced to describe the method/process. Each block illustrated inmay represent one or more processes, methods, or subroutines performed by an electronic device.

7 FIG. The order in which the blocks appear inis for illustration only, and may not be construed to limit the scope of the present disclosure, thus may be different from what is illustrated. Additional blocks may be added or fewer blocks may be utilized without departing from the scope of the present disclosure.

710 700 124 124 At block, the method/processmay start by the decoder modulereceiving the video data. The video data received by the decoder modulemay include a bitstream.

1 2 FIGS.and 120 110 126 126 124 With reference to, the second electronic devicemay receive the bitstream from an encoder, such as the first electronic device(or other video providers) via the second interface. The second interfacemay provide the bitstream to the decoder module.

720 124 At block, the decoder moduledetermines a block unit from a current frame included in the video data.

1 2 FIGS.and 124 124 124 124 With reference to, the decoder modulemay determine the image frames included in the bitstream when the video data received by the decoder moduleis the bitstream. The current frame may be one of the image frames determined according to the bitstream. The decoder modulemay further divide the current frame to determine the block unit according to partition indications in the bitstream. For example, the decoder modulemay divide the current frame to generate multiple CTUs, and further divide a current CTU included in the CTUs to generate multiple divided blocks and to determine the block unit from the divided blocks according to the partition indications based on any video coding standard. The size of the block unit may be Wb×Hb. In some implementations, the values Wb and Hb may be positive integers (e.g., 4, 8, etc.) that may be equal to, or different from, each other.

730 124 At block, the decoder moduledetermines, for the block unit, multiple integer-sample reference blocks and multiple fractional-sample reference blocks from the current frame.

124 The decoder modulemay determine, from the current frame, a reference area of the block unit. The reference area may be reconstructed prior to reconstructing the block unit. The reference area may include multiple reconstructed samples reconstructed prior to reconstructing the block unit.

124 The decoder modulemay determine, from the current frame, multiple search regions based on a location and the size of the block unit. The search regions of the block unit may be determined from the reference area of the current frame. The search regions of the block unit may be included in the current CTU including the block unit and multiple neighboring CTUs neighboring the current CTU. The current CTU and the neighboring CTUs may be included in the reference area of the current frame. The neighboring CTUs may include one or more of a first neighboring CTU located at a top-left side of the current CTU, a second neighboring CTU located above the current CTU, a third neighboring CTU located at an above-right side of the current CTU, and a fourth neighboring CTU located at a left side of the current CTU.

4 FIG.A 4 FIG.B 400 411 414 400 431 435 700 300 730 330 With reference to, the search regions of the block unitmay include the search regions-. With reference to, the search regions of the block unitmay include the search regions-. The search regions of the block unit of the method/processmay be identical to the search regions of the block unit of the method/process. In other words, the search regions of the block unit at blockmay be identical to the search regions of the block unit at block. It should be noted that the number of search regions and the size of search regions may be changed without departing from the scope of the present disclosure.

124 400 411 412 431 436 400 The decoder modulemay determine, for the block unit, multiple reference blocks including the integer-sample reference blocks and the fractional-sample reference blocks from the search regions (e.g., the search regions-or the search regions-) in the current frame. Thus, the integer-sample reference blocks and the fractional-sample reference blocks may be determined from the reference area of the block unit. The size of the block unitmay be identical to the sizes of the integer-sample reference blocks and the fractional-sample reference blocks.

In some implementations, each of the integer-sample reference blocks may include some of the reconstructed samples reconstructed prior to reconstructing the block unit. In some implementations, each of the fractional-sample reference blocks may include multiple fractional-samples determined based on the reconstructed samples. Each of the fractional-samples may be determined based on the reconstructed samples in the reference area by using an interpolation filter. Thus, each of the fractional-sample reference blocks may be determined by using the interpolation filter to filter, respectively, at least one of the reconstructed samples.

700 300 730 330 In some implementations, the fractional-sample reference blocks may be determined based on a fractional precision. The fractional precision may include a half-pel precision, a quarter-pel precision, a 1/16-pel precision, 1/32-pel precision, and/or other fractional precisions. The fractional precision may be determined based on a precision value used in an intra template matching prediction (IntraTMP). In some implementations, a precision flag may be used to determine whether to enable the fractional precision. In some implementations, the precision flag may be included in a syntax header. A syntax level of the syntax header may be higher than, or identical to, a syntax level of a slice header. The precision flag of the method/processmay be identical to the precision flag of the method/process. In other words, the precision flag at blockmay be identical to the precision flag at block.

5 FIG. 523 5232 523 524 5242 524 524 524 5242 524 523 Each of the integer-sample reference blocks may be located at one of multiple integer-sample positions in the current frame, and each of the fractional-sample reference blocks may be located at one of multiple fractional-sample positions in the current frame. With reference to, the location of the integer-sample reference blockmay be represented by an integer-sample positionof a top-left sample of the integer-sample reference block. In addition, the location of the fractional-sample reference blockmay be represented by a fractional-sample positionof a top-left sample of the fractional-sample reference block. Each of the fractional-samples in the fractional-sample reference blockmay be determined by using the interpolation filter to filter, respectively, the neighbors of the reconstructed samples. In some implementations, the top-left sample of the fractional-sample reference blockmay be located at the fractional-sample positionand determined by filtering N neighbors of the reconstructed samples in the reference area. In some implementation, the number N may be an integer, such as 2 or 4. For example, the top-left sample of the fractional-sample reference blockmay be determined by filtering four top-left samples of the integer-sample reference block.

124 124 In some implementations, the decoder modulemay perform a full search on the reference area to determine multiple initial reference blocks. In some such implementations, all of the integer-sample reference blocks may be included in the initial reference blocks during the full search. In some other implementations, all of the integer-sample reference blocks and the fractional-sample reference blocks may be included in the initial reference blocks during the full search. In yet, some other implementations, the decoder modulemay perform a quick search (such as a diamond search) on the reference area to determine the initial reference blocks.

124 124 In some implementations, the decoder modulemay sub-sample the reference area based on the block unit by a sub-sampling factor to determine the initial reference blocks. The sub-sampling factor F may be a positive integer greater than one. The sub-sampling factor F may be determined based on at least one of a predefined factor, a syntax element determined from the video data, the size of the block unit Wb×Hb, a size of the current slice, a size of the reference area, or a size of the current frame. For example, the sub-sampling factor may be equal to 2, 3, 5, or any other integer. The decoder modulemay perform a sparse search by using a sparse grid, determined from the sub-sampling factor F, to search the initial reference blocks. Since the sub-sampling factor F may be changed based on the size of the block unit, the size of the current slice, the slice of the reference area, or the size of the current frame, each divided block in the current frame may have different sub-sampling factors F. Furthermore, the divided blocks in the different frames may also have different sub-sampling factors F. The sub-sampling factor F may be determined for the block unit from the video data.

124 124 The decoder modulemay determine multiple intermediate reference blocks from the initial reference blocks to further perform a refinement search to determine multiple refinement reference blocks. For example, the decoder modulemay sub-sample the reference area based on the block unit by the sub-sampling factor to determine the integer-sample reference blocks, select the intermediate reference blocks from the integer-sample reference blocks, and determine the fractional-sample reference blocks based on the intermediate reference blocks.

7 FIG. 740 124 Referring back to, at block, the decoder moduledetermines multiple integer-sample filter models based on the multiple integer-sample reference blocks.

1 2 FIGS.and 6 FIG.A 124 124 6001 6003 600 With reference to, the decoder modulemay determine a block template region neighboring the block unit from the reference area of the current frame. With reference to, the decoder modulemay determine the block adjacent regions-as a block template region of a block unit.

124 In addition, the decoder modulemay determine multiple reference template regions each neighboring one of the reference blocks from the reference area of the current frame. The reference blocks may include the integer-sample reference blocks. When one of the reference blocks is one of the integer-sample reference blocks, one of the reference template regions corresponding to the one of the reference blocks may be one of multiple integer-sample template regions corresponding to the one of the integer-sample reference blocks.

6 FIG.B 124 6251 6253 625 6002 6003 6252 6253 6001 6003 6251 6253 6002 6003 6252 6253 6001 6003 6251 6253 With reference to, the decoder modulemay further determine the reference adjacent regions-, as a reference template region of a reference block. In some implementations, the heights of the block adjacent regionsandmay be equal to the heights of the reference adjacent regionsand. In addition, the widths of the block adjacent regionsandmay be equal to the widths of the reference adjacent regionsand. In some implementation, the heights of the block adjacent regionsandand the heights of the reference adjacent regionsandmay be equal to 4. In some implementation, the widths of the block adjacent regionsandand the widths of the reference adjacent regionsandmay be equal to 4.

625 600 6251 6253 When the reference blockof the block unitis one of the integer-sample reference blocks, the reference adjacent regions-may be determined as a corresponding one of the integer-sample template regions corresponding to the one of the integer-sample reference blocks.

124 Since the block template region and the integer-sample template regions are reconstructed prior to reconstructing the block unit, the decoder modulemay directly receive multiple reconstructed samples including multiple reconstructed block samples of the block template region and multiple reconstructed reference samples for each of the integer-sample template regions.

124 The decoder modulemay determine multiple reference filter models for the reference blocks. Each of the reference filter models may be determined based on a corresponding one of the reference template regions. Each of the reference filter models may include multiple trained parameters. The trained parameters may be determined for each of the reference filter models by the trained filter mode. The trained filter mode may be used for the calculation by minimizing a mean squared error between the reconstructed block samples in the block template region and the reconstructed reference samples in each of the reference template regions. The reference filter models may be shown as follows:

0 1 5 700 where C is a sample value of a center reference sample to be filter, N is a sample value of a north reference sample located above the center reference sample, S is a sample value of a south reference sample located below the center reference sample, E is a sample value of an cast reference sample located at a right side of the center reference sample, W is a sample value of a west reference sample located at a left side of the center reference sample, B is a bias term, C, C, . . . , and Cis the trained parameters, predVal is a predicted value of a center block sample corresponding to the center reference sample. In some implementations, equation of the reference filter models shown in the method/processis for illustration only, and may not be intended to limit the scope of the present disclosure, thus may be different from what is illustrated. Additional terms may be added or fewer terms may be utilized without departing from the scope of the present disclosure.

124 The reference filter models may include the integer-sample filter models, since the reference blocks include the integer-sample reference blocks. After the trained parameters are derived by the trained filter mode for each of the integer-sample filter models, the decoder modulemay predict the block template region to generate multiple integer-sample predicted regions based on the integer-sample filter models and the integer-sample template regions. Each of the integer-sample predicted regions may include multiple integer-sample predicted samples determined by inputting the reconstructed reference samples in one of the integer-sample reference blocks to a corresponding one of the integer-sample filter models.

124 The decoder modulemay then determine multiple integer-sample template cost values based on the block template region and the integer-sample predicted regions. Each of the integer-sample template cost values may be determined by calculating a difference between the block template region and a corresponding one of the integer-sample predicted regions.

The difference between the reconstructed block samples of the block template region and the integer-sample predicted samples of the corresponding one of the integer-sample predicted regions may be calculated based on a Mean Squared Error (MSE) calculation. In addition, the difference between the block template region and each of the integer-sample predicted regions may be calculated based on a Sum of Absolute Difference (SAD) calculation. In some implementations, the difference between the block template region and each of the integer-sample predicted regions may be calculated based on a Sum of Absolute Transformed Difference (SATD) calculation. In some implementations, the difference between the block template region and each of the integer-sample predicted regions may be calculated based on a mean-removed sum of absolute difference (MR-SAD) calculation.

124 124 124 124 124 In some implementations, when the initial reference blocks are determined from the sparce search, the decoder modulemay use the integer-sample template cost values of the initial reference blocks to determine the intermediate reference blocks. The decoder modulemay determine M intermediate reference blocks from the initial reference blocks based on the cost values. When the initial reference blocks are the integer-sample reference blocks, the decoder modulemay determine M intermediate reference blocks from the integer-sample reference blocks based on the integer-sample template cost values. The decoder modulemay select M integer-sample reference blocks having M minimum values of the integer-sample template cost values. When the intermediate reference blocks are determined, the decoder modulemay further determine the refinement reference blocks based on the intermediate reference blocks.

In some other implementations, since the initial reference blocks may be determined based on the sub-sampling factors, the refinement reference blocks may further include some integer-sample reference blocks, each neighboring one of the intermediate reference blocks, and different from the initial reference blocks. For example, when the sub-sampling factor F is equal to 3 and the fractional precision is the half-pel precision, the number of the refinement reference blocks for each of the intermediate reference blocks may be equal to 5×5.

7 FIG. 750 124 Referring back to, at block, the decoder moduledetermines multiple fractional-sample filter models based on the multiple fractional-sample reference blocks.

6 FIG.B 625 600 6251 6253 The reference blocks may include the fractional-sample reference blocks. When one of the reference blocks is one of the fractional-sample reference blocks, one of the reference template regions corresponding to the one of the reference blocks may be one of multiple fractional-sample template regions corresponding to the one of the fractional-sample reference blocks. With reference to, when the reference blockof the block unitis one of the fractional-sample reference blocks, the reference adjacent regions-may be determined as a corresponding one of the fractional-sample template regions corresponding to the one of the fractional-sample reference blocks.

1 2 FIGS.and 124 Since the block template region and the integer-sample template regions are reconstructed prior to reconstructing the block unit, with reference to, the decoder modulemay directly receive the reconstructed samples including the reconstructed block samples of the block template region and the reconstructed reference samples for the integer-sample template regions. Then, each of the fractional-sample reference blocks may be determined by using an interpolation filter to filter, respectively, at least one of the reconstructed reference samples to generate multiple interpolated samples. The interpolation filter may include multiple interpolation filter coefficients fC and fG.

124 The decoder modulemay determine the reference filter models for the reference blocks. Each of the reference filter models may be determined based on a corresponding one of the reference template regions. Each of the reference filter models may include multiple trained parameters. The trained parameters may be determined for each of the reference filter models by the trained filter mode. The trained filter mode may be used for the calculation by minimizing the mean squared error between the reconstructed block samples in the block template region and the reconstructed reference samples in each of the reference template regions.

124 The reference filter models may include the fractional-sample filter models since the reference blocks include the fractional-sample reference blocks. After the trained parameters are derived by the trained filter mode for each of the fractional-sample filter models, the decoder modulemay predict the block template region to generate multiple fractional-sample predicted regions based on the fractional-sample filter models and the fractional-sample template regions. Each of the fractional-sample predicted regions may include multiple fractional-sample predicted samples determined by inputting the interpolated samples in one of the fractional-sample reference blocks to a corresponding one of the fractional-sample filter models.

124 The decoder modulemay determine multiple fractional-sample template cost values based on the block template region and the fractional-sample predicted regions. Each of the fractional-sample template cost values may be determined by calculating a difference between the block template region and a corresponding one of the fractional-sample predicted regions.

The difference between the reconstructed block samples of the block template region and the fractional-sample predicted samples of the corresponding one of the fractional-sample predicted regions may be calculated based on the MSE calculation. In addition, the difference between the block template region and each of the fractional-sample predicted regions may be calculated based on the SAD calculation. In some implementations, the difference between the block template region and each of the integer-sample predicted regions may be calculated based on the SATD calculation. In some implementations, the difference between the block template region and each of the integer-sample predicted regions may be calculated based on the MR-SAD calculation.

7 FIG. 760 124 Referring back to, at block, the decoder moduleselects at least one prediction reference block from the determined multiple integer-sample reference blocks and the determined multiple fractional-sample reference blocks based on the determined multiple integer-sample template cost values and the determined multiple fractional-sample template cost values.

1 2 FIGS.and 124 With reference to, the decoder modulemay determine an arrangement of the integer-sample reference blocks and the fractional-sample reference blocks based on the integer-sample template cost values and the fractional-sample template cost values, and select the at least one prediction reference block based on the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks.

700 300 760 360 In some implementations, the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks in the method/processmay be identical to the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks in the method/process. In other words, the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks at blockmay be identical to the determined arrangement of the integer-sample reference blocks and the fractional-sample reference blocks at block.

In some implementations, one or more of the prediction reference blocks may be selected from the fractional-sample reference blocks, when the number of the at least one prediction reference block is greater than 1.

124 124 The decoder modulemay select K reference blocks having the least cost values from the integer-sample reference blocks and the fractional-sample reference blocks, and add the selected reference blocks to a reference list. The number K, being a positive integer, may be equal to the number of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list and less than the total number of the integer-sample reference blocks and the fractional-sample reference blocks. In other words, the decoder modulemay select the first to the K-th reference blocks ordered based on the determined arrangement when the integer-sample reference blocks and the fractional-sample reference blocks are reordered in the ascending order of the integer-sample template cost values and the fractional-sample template cost values to generate the determined arrangement. Each of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list may have a reference index value. Thus, the reference index values for the reference list may be within an index range of 0 to K−1 since the number of the integer-sample reference blocks and the fractional-sample reference blocks in the reference list is equal to K.

124 0 1 The decoder modulemay determine the at least one prediction reference block from the integer-sample reference blocks and the fractional-sample reference blocks based on at least one of the determined arrangement or at least one reference block index of the block unit determined based on the bitstream. The at least one reference block index may include at least one indication (e.g., intra TMP_idxand intra TMP_idx). In some implementations, at least one minimum value of the integer-sample template cost values and the fractional-sample template cost values may be determined. Then, at least one of the integer-sample reference blocks and the fractional-sample reference blocks corresponding to the at least one minimum value of the integer-sample template cost values and the fractional-sample template cost values may be directly determined as the at least one prediction reference block without parsing the at least one reference block index. Thus, the number of bits in the bitstream may be reduced.

In some implementations, one or more of the prediction reference blocks may be selected from the fractional-sample reference blocks, when the number of the at least one prediction reference block is greater than 1. Thus, at least one minimum value of the fractional-sample template cost values may be determined, and then at least one of the fractional-sample reference blocks corresponding to the at least one minimum value of the fractional-sample template cost values may be directly determined as the at least one of the prediction reference blocks without parsing the at least one reference block index. In addition, zero or more minimum values of the integer-sample template cost values may be determined, and then zero or more of the integer-sample reference blocks corresponding to the zero or more minimum values of the integer-sample template cost values may be directly determined as the other prediction reference blocks without parsing the at least one reference block index. In some implementations, the number of the zero or more of the integer-sample reference blocks may be determined based on the number of the prediction reference blocks and the number of the at least one of the fractional-sample reference blocks. For example, when all of the prediction reference blocks are selected from the fractional-sample reference blocks, the number of the integer-sample reference blocks included in the prediction reference blocks may be equal to zero.

In some implementations, the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement may be divided into multiple reference block groups. In some implementations, the reference block index may be parsed for the block unit for selecting one of the reference block groups. Thus, all of the prediction reference blocks may be included in the selected one of the reference block groups. In some other implementations, the reference list including the selected reference blocks may be divided into multiple listed block groups. The reference block index may be parsed for the block unit for selecting one of the listed block groups. Thus, all of the prediction reference blocks may be included in the one of the listed block groups.

In some implementations, the at least one reference block index may be parsed for the block unit for selecting the at least one prediction reference block from the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement. In some implementations, the at least one reference block index may be parsed for the block unit for selecting the at least one prediction reference block from the reference list. In some implementations, the reference block having a lower cost value may have a lower reference index value. Thus, since the reference block having a lower cost value may be more easily selected than the reference block having a higher cost value, the number of bits in the bitstream may also be reduced.

In some implementations, one or more of the prediction reference blocks may be selected from the fractional-sample reference blocks, when the number of the at least one prediction reference block is greater than 1. Thus, one or more of the reference block indices may be parsed for the block unit for selecting the one or more of the prediction reference blocks only from the fractional-sample reference blocks arranged based on the determined arrangement when the number of the at least one prediction reference block is greater than 1. In addition, the other reference block indices may be parsed for the block unit for selecting the other prediction reference blocks only from the integer-sample reference blocks arranged based on the determined arrangement. In some other implementations, one of the reference block indices may be parsed for the block unit for selecting one of the prediction reference blocks only from the fractional-sample reference blocks arranged based on the determined arrangement when the number of the at least one prediction reference block is greater than 1. In addition, the other reference block indices may be parsed for the block unit for selecting the other prediction reference blocks from the integer-sample reference blocks and the fractional-sample reference blocks arranged based on the determined arrangement.

700 300 760 360 The selection of the at least one prediction reference block in the method/processmay be identical to the selection of the at least one prediction reference block in the method/process. In other words, the selection of the at least one prediction reference block at blockmay be identical to the selection of the at least one prediction reference block at block.

7 FIG. 770 124 Referring back to, at block, the decoder modulereconstructs the block unit based on the multiple prediction reference blocks.

124 When the at least one prediction reference block is determined, the decoder modulemay predict the block unit to generate at least one block predicted region based on the at least one prediction reference block and at least one of the reference filter models, each corresponding to one of the at least one prediction reference block. Each of the at least one block predicted region may include multiple block predicted samples determined by inputting multiple prediction reference samples in one of the at least one prediction reference block to a corresponding one of the at least one of the reference filter models. When one of the at least one prediction reference block is one of the integer-sample reference blocks, the prediction reference samples in the one of the at least one prediction reference block may be the reconstructed samples in the one of the integer-sample reference blocks. When one of the at least one prediction reference block is one of the fractional-sample reference blocks, the prediction reference samples in the one of the at least one prediction reference block may be the fractional-samples in the one of the fractional-sample reference blocks.

1 2 FIGS.and 124 124 With reference to, the decoder modulemay determine multiple weighting parameters based on the integer-sample template cost values and the fractional-sample template cost values for the prediction reference blocks when the number of the at least one prediction reference block is greater than 1. The decoder modulemay compare the integer-sample template cost values and the fractional-sample template cost values of the prediction reference blocks to determine the weighting parameters. For example, the number of the prediction reference blocks may be equal to Nb, and the number Nb may be a positive integer greater than 1. Thus, the weighting parameters of the Nb prediction reference blocks may be determined based on the following functions:

RBi 1 2 N where the numbers wis a weighting parameter of i-th prediction reference block, RC, RC, . . . , and RCare the cost values of the prediction reference blocks, and the number i are less than or equal to the number Nb. When the i-th prediction reference block is one of the integer-sample reference blocks, the cost value of the i-th prediction reference block is one of the integer-sample template cost values corresponding to the one of the integer-sample reference blocks. When the i-th prediction reference block is one of the fractional-sample reference blocks, the cost value of the i-th prediction reference block is one of the fractional-sample template cost values corresponding to the one of the fractional-sample reference blocks.

124 124 The decoder modulemay predict the block unit based on the weighting parameters and the block predicted regions corresponding to the prediction reference blocks when the number of the at least one prediction reference block is greater than 1. The decoder modulemay weightedly combine the block predicted regions to determine a predicted block of the block unit based on the block predicted regions and the weighting parameters.

124 In some other implementations, the decoder modulemay directly determine one block predicted regions as the predicted block of the block unit when the number of the at least one prediction reference block is equal to 1.

124 124 124 700 The decoder modulemay reconstruct the block unit based on the predicted block. The decoder modulemay determine multiple residual components from the bitstream for the block unit and add the residual components into the predicted block to reconstruct the block unit. The decoder modulemay reconstruct all of the other block units in the image frame for reconstructing the image frame and the video. The method/processmay then end.

8 FIG. 1 FIG. 114 110 114 8141 8142 8145 8143 8144 8146 8147 8148 8141 114 81411 81412 81413 114 is a block diagram illustrating an encoder moduleof the first electronic deviceillustrated in, in accordance with one or more example implementations of this disclosure. The encoder modulemay include a prediction processor (e.g., a prediction processing unit), at least a first summer (e.g., a first summer) and a second summer (e.g., a second summer), a transform/quantization processor (e.g., a transform/quantization unit), an inverse quantization/inverse transform processor (e.g., an inverse quantization/inverse transform unit), a filter (e.g., a filtering unit), a decoded picture buffer (e.g., a decoded picture buffer), and an entropy encoder (e.g., an entropy encoding unit). The prediction processing unitof the encoder modulemay further include a partition processor (e.g., a partition unit), an intra prediction processor (e.g., an intra prediction unit), and an inter prediction processor (e.g., an inter prediction unit). The encoder modulemay receive the source video and encode the source video to output a bitstream.

114 The encoder modulemay receive source video including multiple image frames and then divide the image frames according to a coding structure. Each of the image frames may be divided into at least one image block.

The at least one image block may include a luminance block having multiple luminance samples and at least one chrominance block having multiple chrominance samples. The luminance block and the at least one chrominance block may be further divided to generate macroblocks, CTUs, CBs, sub-divisions thereof, and/or other equivalent coding units.

114 The encoder modulemay perform additional sub-divisions of the source video. It should be noted that the disclosed implementations are generally applicable to video coding regardless of how the source video is partitioned prior to and/or during the encoding.

8141 During the encoding process, the prediction processing unitmay receive a current image block of a specific one of the image frames. The current image block may be the luminance block or one of the chrominance blocks in the specific image frame.

81411 81412 81413 The partition unitmay divide the current image block into multiple block units. The intra prediction unitmay perform intra-predictive coding of a current block unit relative to one or more neighboring blocks in the same frame as the current block unit in order to provide spatial prediction. The inter prediction unitmay perform inter-predictive coding of the current block unit relative to one or more blocks in one or more reference image blocks to provide temporal prediction.

8141 81412 81413 The prediction processing unitmay select one of the coding results generated by the intra prediction unitand the inter prediction unitbased on a mode selection method, such as a cost function. The mode selection method may be a rate-distortion optimization (RDO) process.

8141 8142 8145 8141 8148 The prediction processing unitmay determine the selected coding result and provide a predicted block corresponding to the selected coding result to the first summerfor generating a residual block and to the second summerfor reconstructing the encoded block unit. The prediction processing unitmay further provide syntax elements, such as motion vectors, intra-mode indicators, partition information, and/or other syntax information, to the entropy encoding unit.

81412 81412 The intra prediction unitmay intra-predict the current block unit. The intra prediction unitmay determine an intra prediction mode directed toward a reconstructed sample neighboring the current block unit in order to encode the current block unit.

81412 81412 8141 81412 81412 The intra prediction unitmay encode the current block unit using various intra prediction modes. The intra prediction unitof the prediction processing unitmay select an appropriate intra prediction mode from the selected modes. The intra prediction unitmay encode the current block unit using a cross-component prediction mode to predict one of the two chroma components of the current block unit based on the luma components of the current block unit. The intra prediction unitmay predict a first one of the two chroma components of the current block unit based on the second of the two chroma components of the current block unit.

81413 81412 81413 The inter prediction unitmay inter-predict the current block unit as an alternative to the intra prediction performed by the intra prediction unit. The inter prediction unitmay perform motion estimation to estimate motion of the current block unit for generating a motion vector.

81413 8147 The motion vector may indicate a displacement of the current block unit within the current image block relative to a reference block unit within a reference image block. The inter prediction unitmay receive at least one reference image block stored in the decoded picture bufferand estimate the motion based on the received reference image blocks to generate the motion vector.

8142 8141 8142 The first summermay generate the residual block by subtracting the prediction block determined by the prediction processing unitfrom the original current block unit. The first summermay represent the component or components that perform this subtraction.

8143 The transform/quantization unitmay apply a transform to the residual block in order to generate a residual transform coefficient and then quantize the residual transform coefficients to further reduce the bit rate. The transform may be one of a DCT, DST, AMT, MDNSST, HyGT, signal-dependent transform, KLT, wavelet transform, integer transform, sub-band transform, and a conceptually similar transform.

The transform may convert the residual information from a pixel value domain to a transform domain, such as a frequency domain. The degree of quantization may be modified by adjusting a quantization parameter.

8143 8148 The transform/quantization unitmay perform a scan of the matrix including the quantized transform coefficients. Alternatively, the entropy encoding unitmay perform the scan.

8148 8141 8143 8148 The entropy encoding unitmay receive multiple syntax elements from the prediction processing unitand the transform/quantization unit, including a quantization parameter, transform data, motion vectors, intra modes, partition information, and/or other syntax information. The entropy encoding unitmay encode the syntax elements into the bitstream.

8148 120 1 FIG. The entropy encoding unitmay entropy encode the quantized transform coefficients by performing CAVLC, CABAC, SBAC, PIPE coding, or another entropy coding technique to generate an encoded bitstream. The encoded bitstream may be transmitted to another device (e.g., the second electronic device, as shown in) or archived for later transmission or retrieval.

8144 8145 8141 8147 The inverse quantization/inverse transform unitmay apply inverse quantization and inverse transformation to reconstruct the residual block in the pixel domain for later use as a reference block. The second summermay add the reconstructed residual block to the prediction block provided by the prediction processing unitin order to produce a reconstructed block for storage in the decoded picture buffer.

8146 8145 The filtering unitmay include a deblocking filter, an SAO filter, a bilateral filter, and/or an ALF to remove blocking artifacts from the reconstructed block. Other filters (in loop or post loop) may be used in addition to the deblocking filter, the SAO filter, the bilateral filter, and the ALF. Such filters are not illustrated for brevity and may filter the output of the second summer.

8147 814 8147 8147 114 The decoded picture buffermay be a reference picture memory that stores the reference block to be used by the encoder moduleto encode video, such as in intra-coding or inter-coding modes. The decoded picture buffermay include a variety of memory devices, such as DRAM (e.g., including SDRAM), MRAM, RRAM, or other types of memory devices. The decoded picture buffermay be on-chip with other components of the encoder moduleor off-chip relative to those components.

300 110 310 300 114 114 320 114 114 1 3 8 FIGS.,, and The method/processfor decoding and/or encoding video data may be performed by the first electronic device. With reference to, at block, the method/processmay start by the encoder modulereceiving the video data. The video data received by the encoder modulemay be a video. At block, the encoder modulemay determine a block unit from a current frame included in the video data. The encoder modulemay divide the current frame to generate multiple CTUs, and further divide a current CTU included in the CTUs to generate multiple divided blocks and to determine the block unit from the divided blocks according to the partition indications based on any video coding standard.

330 114 114 124 At block, the encoder modulemay determine, for the block unit, multiple integer-sample reference blocks and multiple fractional-sample reference blocks from the current frame. The integer-sample reference blocks and the fractional-sample reference blocks of the block unit determined by the encoder modulemay be identical to the integer-sample reference blocks and the fractional-sample reference blocks of the block unit determined by the decoder module.

340 114 350 114 114 124 At block, the encoder modulemay determine multiple integer-sample template cost values based on the multiple integer-sample reference blocks. At block, the encoder modulemay determine multiple fractional-sample template cost values based on the multiple fractional-sample reference blocks. The integer-sample template cost values and the fractional-sample template cost values for the block unit determined by the encoder modulemay be identical to the integer-sample template cost values and the fractional-sample template cost values for the block unit determined by the decoder module.

360 114 114 114 124 At block, the encoder moduleselects multiple prediction reference blocks from the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values. When the block unit is reconstructed by the encoder module, the selection of the prediction reference blocks by the encoder modulemay be identical to the selection of the prediction reference blocks by the decoder module.

114 114 114 114 124 370 114 114 114 8142 8145 114 8148 When the block unit is predicted by the encoder module, the encoder modulemay generate multiple sets of the prediction reference blocks from the integer-sample reference blocks and the fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values. Then, the encoder modulemay predict the block unit based on the multiple sets of the prediction reference blocks to generate multiple first predicted results of the block unit. The prediction for generating one of the first predicted results of the block unit by the encoder modulemay be identical to the prediction for generating the predicted block of the block unit by the decoder moduleat block. The encoder modulemay predict the block unit based on other prediction modes to generate multiple second predicted results. The encoder modulemay select one of the first predicted results and the second predicted results based on a mode selection method, such as a cost function. The mode selection method may be a rate-distortion optimization (RDO) process. The encoder modulemay provide the selected coding result to the first summerfor generating a residual block and to the second summerfor reconstructing the encoded block unit. The encoder modulemay further provide syntax elements, such as motion vectors, intra-mode indicators, partition information, and/or other syntax information, to the entropy encoding unit.

370 114 114 124 300 114 At block, the encoder modulemay reconstruct the block unit based on the multiple prediction reference blocks. The reconstruction of the block unit by the encoder modulemay be identical to the reconstruction of the block unit by the decoder module. The method/processfor the encoder modulemay then end.

700 110 710 300 114 114 720 114 114 1 7 8 FIGS.,, and The method/processfor decoding and/or encoding video data may be performed by the first electronic device. With reference to, at block, the method/processmay start by the encoder modulereceiving the video data. The video data received by the encoder modulemay be a video. At block, the encoder modulemay determine a block unit from a current frame included in the video data. The encoder modulemay divide the current frame to generate multiple CTUs, and further divide a current CTU included in the CTUs to generate multiple divided blocks and to determine the block unit from the divided blocks according to the partition indications based on any video coding standard.

730 114 114 124 At block, the encoder modulemay determine, for the block unit, multiple integer-sample reference blocks and multiple fractional-sample reference blocks from the current frame. The integer-sample reference blocks and the fractional-sample reference blocks of the block unit determined by the encoder modulemay be identical to the integer-sample reference blocks and the fractional-sample reference blocks of the block unit determined by the decoder module.

740 114 750 114 114 124 At block, the encoder modulemay determine multiple integer-sample filter models based on the multiple integer-sample reference blocks. At block, the encoder modulemay multiple fractional-sample filter models based on the multiple fractional-sample reference blocks. The integer-sample filter models and the fractional-sample filter models for the block unit determined by the encoder modulemay be identical to the integer-sample filter models and the fractional-sample filter models for the block unit determined by the decoder module.

760 114 114 114 124 At block, the encoder moduleselects at least one prediction reference block from the multiple integer-sample reference blocks and the multiple fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values. When the block unit is reconstructed by the encoder module, the selection of the at least one prediction reference block by the encoder modulemay be identical to the selection of the at least one prediction reference block by the decoder module.

114 114 114 114 124 770 114 114 114 8142 8145 114 8148 When the block unit is predicted by the encoder module, the encoder modulemay generate multiple sets of the at least one prediction reference block from the integer-sample reference blocks and the fractional-sample reference blocks based on the multiple integer-sample template cost values and the multiple fractional-sample template cost values. Then, the encoder modulemay predict the block unit based on the multiple sets of the at least one prediction reference block to generate multiple first predicted results of the block unit. The prediction of one of the first predicted results of the block unit by the encoder modulemay be identical to the prediction of the predicted block of the block unit by the decoder moduleat block. The encoder modulemay predict the block unit based on other prediction modes to generate multiple second predicted results. The encoder modulemay select one of the first predicted results and the second predicted results based on a mode selection method, such as a cost function. The mode selection method may be a rate-distortion optimization (RDO) process. The encoder modulemay provide the selected coding result to the first summerfor generating a residual block and to the second summerfor reconstructing the encoded block unit. The encoder modulemay further provide syntax elements, such as motion vectors, intra-mode indicators, partition information, and/or other syntax information, to the entropy encoding unit.

770 114 114 124 700 114 At block, the encoder modulemay reconstruct the block unit based on the at least one prediction reference block. The reconstruction of the block unit by the encoder modulemay be identical to the reconstruction of the block unit by the decoder module. The method/processfor the encoder modulemay then end.

The disclosed implementations are to be considered in all respects as illustrative and not restrictive. It should also be understood that the present disclosure is not limited to the specific disclosed implementations, but that many rearrangements, modifications, and substitutions are possible without departing from the scope of the present disclosure.